In general, a body-acoustic device of the above type includes a housing wherein an inner space of the housing is divided into two parts by a diaphragm having an opening for mounting a loudspeaker. When the loudspeaker is operated, sound pressure from the loudspeaker vibrates the outer walls of the housing.
An example of such a sonic body resonator is disclosed in the Japanese Patent Application Laid-Open 2-266797. Particularly, FIG. 4 of this laid-open application discloses a loudspeaker housing comprising a pair of dish-shaped vibrating elements joined together to form a discoid. The inner space of this discoidal housing is divided, in its thickness direction, into two parts by a diaphragm made of a relatively hard material such as wood, and the diaphragm has an opening for mounting a loudspeaker.
However, a problem with this type of body-acoustic device is that when the inner spaces of the housing are completely segregated from each other by the diaphragm, it becomes impossible to vibrate the entire outer wall of the housing, failing to produce satisfactory body-acoustic effect.
The loudspeaker mounted to the diaphragm may be made to have a larger diameter and a larger output for increasing vibration propagated on the outside wall of the housing while also enhancing bass sound. However, this measure makes it necessary to increase the overall size of the housing for accommodating the diametrically larger loudspeaker, resulting in a weight increase of the body-acoustic device and a higher manufacturing cost. Thus, the body-acoustic device becomes unsuitable as a peripheral device for a low-cost video game system.
It is, therefore, an object of the present invention to provide a body-acoustic device wherein a diametrically small speaker having a small output can provide sufficient body vibration as well as sufficient propagation of bass sound.
Another object of the present invention is to provide a small and light sonic body resonator which can be manufactured at a low cost but yet create sufficient body-felt sound effect.